Hi
<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
Thanks for your inquiry. Replacement string should not contain special characters. However, if you need to replace with text, which contains special characters, you can use ReplaceEvaluator. Please see the following link for more information:
http://www.aspose.com/documentation/.net-components/aspose.words-for-.net-and-java/aspose.words.range.replace_overload_3.html
Hope this helps. Please let me know in case of any issues, I will be glad to help you.
Best regards.